Complete Hematologic and Cytogenetic Remission of Acute Myeloid Leukemia in an Elderly Patient Treated with Decitabine and Venetoclax: A Case Report

We present the case of a 77 year old woman, Caucasian, with medical history of diabetes mellitus, hyperthyroidism, hypertension and hyperlipidemia, that suddenly develops progressive articular pain, dyspnea at rest, easy bruising /ecchymosis in soft tissues, weakness and nose bleeding. At admission no visceromegaly was noted, gums and lymph nodes were normal. Initial lab workup showed severe anemia (Hb 7.7 g/dL), leukocytosis (19.1 x 10^3/uL) with monocytosis (51%) and left shift, severe thrombocytopenia (Plt 33 x 10^3/uL), hyperfibrinogenemia, hyperglycemia and hyperuricemia. Bone marrow morphology was conclusive of Acute Myeloid Leukemia with 45 % of blasts, hypercellular with progressive trilineage hematopoiesis and no ringed sideroblasts. Flow cytometry of peripheral blood detected only 0.8 % of blasts (CD34+) with positive myeloid markers. Flow cytometry of bone marrow detected 17 % of myeloid blasts expressing CD34+, HLA-DR, CD117, cytoplasmic (cy) MPO, CD13, partial CD11b, negative for cyTdT and cy CD79a. Genetically, 5q31/EGR1 deletion (86%) and gain of 20q12 (64%), with no other anomalies or mutations were found.

Patient was treated with Decitabine 20mg/m2 IV daily x 10 d, followed by Venetoclax starting gradually from 100 mg escalating up to 300 mg oral as induction therapy. Complications during this phase were pleural effusion, C. difficile-associated diarrhea, urinary infection due to Enterococcus faecium, anemia, thrombocytopenia that required blood and platelet transfusions. After the first cycle of therapy a new bone marrow done showed morphologically < 2 % of blasts with moderate pancytopenia, but presence still of 10 % of CD34+ myeloblasts detected by flow cytometry. After a second course of therapy Decitabine/Venetoclax, peripheral blood leukocytes and platelets normalized, persisting only moderate anemia with no transfusion requirements. Bone marrow FISH report was normal, Del 5q disappeared, no detection of aberrations associated to myelodysplastic syndrome, and no detection of other abnormalities (results below the cut-off) were described, however a new pathogenic alteration in the DNMT3A gene not described before in other cases was detected with the New Generation System analysis.

At the moment of presenting this case report there is a leukemia-free survival of 6 months, with impressing improvement in the general status.

Conclusion: Therapy with the combination Decitabine/Venetoclax is a good alternative for treating elderly patients with AML, sparing the aggressiveness of regular induction chemotherapies and a tremendous impact in inducing cytogenetic remission.